Question: Simplify the following expression: ${-3(-7+5r)+2(-2r-1)}$
Solution: Distribute the ${-3}$ into the first set of parentheses: $ {-3(}\gray{-7+5r}{)} + 2(-2r-1) $ $ {21-15r} + 2(-2r-1) $ Distribute the ${2}$ into the parentheses: $ 21-15r + {2(}\gray{-2r-1}{)} $ $ 21-15r {-4r-2} $ Rewrite the expression to group the ${r}$ terms and numeric terms: $ {-15r - 4r} + {21 - 2}$ Combine the ${r}$ terms: $ {-19r} + {21 - 2}$ Combine the numeric terms: $ {-19r} + {19}$ The simplified expression is $-19r+19$